Influence of alumina addition on grain growth and room temperature mechanical properties of 8YSCZ/Al 2O 3 composites

Abstract

The effect of the amount of alumina addition on grain growth and room temperature mechanical properties (hardness and fracture toughness) of 8YSCZ/Al 2O 3 composites were determined using 8 mol% yttria-stabilized cubic zirconia (8YSCZ) and various amounts of Al 2O 3 (0–10 wt%). The experimental results showed that the grain growth in Al 2O 3 doped 8YSCZs occured slowly and more sluggish than that in undoped 8YSCZ. Also, the grain growth rate decreased with increasing Al 2O 3 content. The grain growth exponent value and the activation energy for undoped 8YSCZ were found to be 2 and 289 kJ/mol, respectively. The addition of Al 2O 3 raised the grain growth exponent value to 3 and activation energy for the grain growth process was increased from 289 to 410 kJ/mol. Also, the introduction of Al 2O 3 enhanced the hardness and fracture toughness of 8YSCZ/Al 2O 3 composites. The hardness and fracture toughness increased with increasing Al 2O 3 content. The maximum hardness and fracture toughness values reached 1459 kgf/mm 2 and 2.41 MPa m 1/2, respectively, with the addition of 10 wt% Al 2O 3 while these values were 1314 kgf/mm 2 and 1.5 MPa m 1/2 for undoped 8YSCZ.